By examining 'echoes' of infrared light, scientists were able to measure the intensity of black hole flares.
When objects approach a black hole, they become stretched under immense gravitational force – a phenomenon fittingly known as “spaghettification.” The black hole then devours its cosmic meal, before finally letting loose a massive, flaming cosmic belch.
For the first time, scientists have recorded this explosive event. By examining infrared light from black hole disruptions, which is captured and “echoed” by surrounding space dust, two separate research teams were able to measure the intensity of the flares.
snip-------------
http://www.csmonitor.com/Science/2016/0919/Black-holes-belch-fire-after-eating-cosmic-spaghetti-studies-show